(1) Field of the Invention
The invention relates to a plaster which is ready for use for skin patch tests, has occlusion chambers and contains test allergens. Each test allergen is in a semiliquid vehicle with doses of defined volume in the occlusion chambers and is enveloped in a protective pack. This test plaster can be used for the detection of allergic reactions in the diagnosis of allergies.
(2) Prior Art
Plasters which have occlusion chambers for skin patch tests are known. A particularly distinguished position in the field is occupied in the present-day patch testing by the Finn Chamber Test of V. Pirila (compare H.-J. Bandmann and S. Fregert, Epicutan-Testung (Patch testing) published by Springer, Berlin Heidelberg New York, 1982, page 43; German Offenlegungsschrift No. 2,420,345) in which, before the actual test, the test substances are introduced manually into occlusion chambers which are made of aluminum.
It is important that the quantity of allergen introduced into these chambers be extremely accurate (compare T. Fischer and H. Maibach, Contact Dermatitis 11 (3), pages 137-140 (1984). This is because there may be false-positive or false-negative results in the test if the amounts introduced are not uniform, despite the test substances being standardized and manufactured industrially. This fact can crucially effect and impair the validity of patch tests. Moreover, if too much test substance is introduced into a chamber, the test plaster may become detached from the patient's skin.
In particular, under the conditions of routine procedure in a medical practice, it is frequently impossible to measure the amounts of allergen introduced into the chambers with sufficient accuracy. Moreover, accurate application of customary test ointments from small vials or syringes demands considerable time, experience and patience.